Coal mining deaths surged in the U.S. in 2017, one year after they hit a record low.

The nation's coal mines recorded 15 deaths last year, including eight in West Virginia. Kentucky had two deaths, and there were one each in Alabama, Colorado, Montana, Pennsylvania and Wyoming. In 2016 there were eight U.S. coal mine deaths.

West Virginia has led the nation in coal mining deaths in six of the past eight years. That includes 2010, when 29 miners were killed in an explosion at the Upper Big Branch mine in southern West Virginia.

In September, President Donald Trump appointed retired coal company executive David Zatezalo as the new chief of the Mine Safety and Health Administration. Most of the deaths this year occurred before his appointment. The Wheeling resident retired in 2014 as chairman of Rhino Resources.

Zatezalo was narrowly approved by the Senate in November. His appointment was opposed by Sen. Joe Manchin, D-W.Va., who said he was not convinced Zatezalo was suited to oversee the federal agency that implements and enforces mine safety laws and standards.

Last month the Trump administration brought up for review standards implemented by Barack Obama's administration that lowered the allowable limits for miners' exposure to coal dust. MSHA indicated it is reconsidering rules meant to protect underground miners from breathing coal and rock dust — the cause of black lung — and diesel exhaust, which can cause cancer.

Eight coal mining deaths this year involved hauling vehicles and two others involved machinery. None were attributed to an explosion of gas or dust, which was to blame for the Upper Big Branch disaster.

The number of coal mining fatalities was under 20 for the fourth straight year after reaching exactly 20 in 2011, 2012 and 2013. By comparison, in 1966, the mining industry counted 233 deaths. A century ago there were 2,226.

MSHA has attributed low numbers in previous years to far fewer coal mining jobs and tougher enforcement of mining safety rules. Zatezalo, who said in October that his first priority was preventing people from getting hurt, didn't immediately respond to a request for comment left with MSHA on Tuesday.

There have been 13 fatalities in 2017 in non-coal mines that produce gravel, sand, limestone and mineable metals. There also were 17 such deaths in 2015 and 30 in 2014.

Appalachia has been especially hit hard by the closing of dozens of mines in recent years, but there was a turnaround in production in 2017.

According to the Energy Information Administration's weekly estimates, U.S. coal production increased 8.9 percent in the 52 weeks ending Dec. 23, the latest available. Production in West Virginia increased 16 percent, including 25 percent in coal-rich southern West Virginia.

Wyoming, the top coal-producing state, saw a 10.7 percent increase and Pennsylvania had an 11.6 percent hike.

There were about 92,000 working miners in the United States in 2011, compared with about 52,000 in 2016, the lowest figure since the Energy Information Administration began collecting data in 1978. The 2017 numbers are not yet available.